Self-Biased Amplifier Circuit With Output-Controlled Standby Biasing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Self-biased amplifier circuits face challenges in achieving low power consumption while maintaining compactness, as additional switches required for shutdown operations can degrade performance and increase circuit size, especially in applications like analog-to-digital converters and clock buffers.
Innovation Solution
A self-biased amplifier circuit design incorporating complementary PMOS and NMOS transistors with transistor switches connected between output nodes and bias transistor gates, allowing for selective control between active and standby modes, reducing current flow through switches and minimizing performance impact, enabling a compact and low-power design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If additional switches are added to shut down the circuit when not in use, then power consumption is reduced, but circuit area increases and performance degrades
Solution Approach 1:
The patent merges the shutdown function with the existing self-biasing structure by using the output node to control the bias transistors through transistor switches. This integration eliminates the need for separate shutdown switches, achieving power reduction without increasing circuit area.
Solution Approach 2:
The circuit uses its own output signal to control the bias transistors via the transistor switches, creating a self-managed shutdown mechanism. The output node automatically controls the bias current based on operational state, eliminating external control circuits.
2Loss of energy
If additional switches are added to shut down the circuit when not in use, then power consumption is reduced, but circuit performance degrades
Solution Approach 1:
The shutdown function is merged with the self-biasing operation, using the same transistor switches that control bias current to enable/disable the circuit. This unified approach ensures that performance-critical signal paths remain untouched while power consumption is reduced through bias current control.
Solution Approach 2:
The patent changes the bias current parameter dynamically based on operational state. By controlling the gate voltage of bias transistors through transistor switches, the circuit transitions between full-power operation and low-power standby without degrading signal integrity in active mode.
3Loss of energy
If transistor switches are used to control active and standby modes, then power consumption is reduced, but on-resistance increases affecting performance
Solution Approach 1:
The transistor switches are placed only in the bias current path, not in the signal path. This localized placement ensures that the switches' on-resistance affects only the bias current control, while the high-speed signal paths maintain their low impedance characteristics, minimizing performance impact.
Solution Approach 2:
The patent uses simple transistor switches with acceptable on-resistance values, relying on the self-biasing structure to compensate for resistance effects. The design accepts moderate on-resistance in the bias path since it does not directly affect signal integrity, simplifying the switch requirements.
Data Source
AI summary
A self-biased amplifier circuit, comprises: an input, wherein the input comprises input transistors forming inverters; bias transistors, wherein a source of each input transistor is connected to a drain of a bias transistor for providing a bias current to the inverters; an output connected to a first output node and/or a second output node; and pairs of transistor switches connected between the first or the second output node and a respective gate of the bias transistors, wherein the pairs of transistor switches are configured to control the self-biased amplifier circuit to assume an active mode or a standby mode.